Table 4: Rabbit cytosolic SHMT structures compared in this study. The table shows the cofactor form and the ligand present in each subunit of the structures.

EnzymeChainFormLigand

Unliganded wild typeAi.a.
Bi.a.
Ci.a.MES
Di.a.MES

Unliganded
T254A
Ai.a.
Bi.a.
Ci.a.
Di.a.

T254A + glycineAg.d.Gly.
Bg.d.Gly.
Cg.d.Gly.
Dg.d.Gly.

T254A + L-serineAg.d.L-Ser.
Bg.d.L-Ser.
Cg.d.L-Ser.
Dg.d.L-Ser.

Unliganded
T254C
Ai.a.H2O
Bi.a.H2O
Ci.a.H2O
Di.a.PO4

T254C + glycineAg.d.Gly.
Bg.d.Gly.

T254C + L-serineAg.d.L-Ser.
Bg.d.L-Ser.
Cg.d.L-Ser.
Dg.d.L-Ser.

Wild type + glycine + 5-CHO-H4PteGlu3Ag.d.Gly.
Bi.a.
Cg.d.Gly.
Di.a.

i.a.: internal aldimine.
g.d.: gem-diamine.
MES: 2-(N-morpholino)ethanesulfonate.
5-CHO-H4PteGlu3: triglutamic form of 5-formyltetrahydrofolate.